<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        .box {
            width: 0;
            border-top: 50px solid red;
            border-bottom: 50px solid blue;
            border-left: 50px solid yellow;
            border-right: 50px solid pink;
            /* border-color: red yellow green blue; */
        
        }
        i {
  border: solid black;
  border-width: 0 1px 1px 0;
  display: inline-block;
  padding: 3px;
}

.right {
  transform: rotate(-45deg);
  -webkit-transform: rotate(-45deg);
}

.left {
  transform: rotate(135deg);
  -webkit-transform: rotate(135deg);
}

.up {
  transform: rotate(-135deg);
  -webkit-transform: rotate(-135deg);
}

.down {
  transform: rotate(45deg);
  -webkit-transform: rotate(45deg);
}
    </style>
</head>
<body>
    <div class="box"></div>
    <p>Right arrow: <i class="right"></i></p>
<p>Left arrow: <i class="left"></i></p>
<p>Up arrow: <i class="up"></i></p>
<p>Down arrow: <i class="down"></i></p>
</body>
</html>